Technical Field
The present invention relates to an occupant protection device.
Related Art
Airbag devices are known in which gas from an inflator is supplied through a gas supply pipe fixed to a seatback to a bag attached to the gas supply pipe, and the bag is inflated so as to surround an occupant from the front and the side in a collision (see Japanese Patent Application Laid-Open (JP-A) No. 2000-344044). Airbag devices are also known in which head airbags protrude out from left and right end portions of a seat headrest toward the front, and join up in front of the head of an occupant, and an auxiliary head airbag protrudes out toward the front from a central portion of the headrest and joins up with the pair of head airbags (see JP-A No. 2013-018378).
In the configuration of JP-A No. 2000-344044, the gas supply pipe is provided projecting out above the seatback, and so the appearance is negatively affected and the gas supply pipe becomes an interference when the vehicle seat is operated. These issues are resolved by a configuration in which the head airbags are housed inside the headrest, as described in JP-A No. 2013-018378. In the configuration of JP-A No. 2013-018378, it is difficult to secure joint strength between the pair of head airbags that are joined together after inflation and deployment, and joint strength of the auxiliary head airbag with respect to the pair of head airbags.
As a countermeasure thereto, it would be conceivable to adopt a configuration in which an airbag, configured as an integral bag body and housed inside the headrest or the seatback, is inflated and deployed so as to surround the head of an occupant from the seat front side and both seat width direction sides. In such a configuration, part of the airbag is inflated and deployed passing over the head of the occupant, and so there is room for improvement from the perspective of inflating and deploying a front inflating portion at the seat front side of the head of the occupant. Specifically, deployment performance of the airbag to inflate and deploy the front inflating portion in front of the head of the occupant, and restraint performance of the head of the occupant by the front inflating portion, are both required.